Edge-Core ECS4120-28F, Справочное руководство, Страница: 576 / 938

Chapter 21
| VLAN Commands
Configuring IEEE 802.1Q Tunneling
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VLAN that will carry this traffic across the 802.1Q tunnel. This process is
performed in a transparent manner.
◆
When priority bits are found in the inner tag, these are also copied to the outer
tag. This allows the service provider to differentiate service based on the
indicated priority and appropriate methods of queue management at
intermediate nodes across the tunnel.
◆
Rather than relying on standard service paths and priority queuing, QinQ VLAN
mapping can be used to further enhance service by defining a set of
differentiated service pathways to follow across the service provider’s network
for traffic arriving from specified inbound customer VLANs.
◆
Note that all customer interfaces should be configured as access interfaces
(that is, a user-to-network interface) and service provider interfaces as uplink
interfaces (that is, a network-to-network interface). Use the
switchport
dot1q-tunnel mode uplink command to set an interface to access or uplink
mode.
◆
When the remove-ctag option is specified, the inner-tag containing the
customer’s VID is removed, and the outer-tag containing the service provider’s
VID remains in place.
Example
This example sets the SVID to 99 in the outer tag for egress packets exiting port 1
when the packet’s CVID is 2.
Console(config)#interface ethernet 1/1
Console(config-if)#switchport dot1q-tunnel service 99 match cvid 2
Console(config-if)#
The following example maps C-VLAN 10 to S-VLAN 100, C-VLAN 20 to S-VLAN 200
and C-VLAN 30 to S-VLAN 300 for ingress traffic on port 1 of Switches A and B.
Figure 7: Mapping QinQ Service VLAN to Customer VLAN
Switch C
Switch B Switch A
Port 1
Port 2
Port 1
Port 2 Port 2
Port 1
[SVID 100, CVID 10]
[SVID 200, CVID 20]
[SVID 300, CVID 30] [SVID 100, CVID 10]
[SVID 200, CVID 20]
[SVID 300, CVID 30]
[VID 10]
[VID 20]
[VID 30] [VID 10]
[VID 20]
[VID 30]